The main objective of the proposed research is to study the anatomical and physiological organization of visual-sensory, visuomotor and multimodal systems at one of their more advanced stages of evolution with the use of contemporary neuroanatomical and electrophysiological techniques. The anatomical techniques include anterograde tracing methods such as selective silver staining of degenerated axons and axon terminals and axonal transport of incorporated tritiated amino acids; and retrograd axonal transport of the enzyme, horseradish peroxidase. The electrophysiological techniques include intra- and extracellular recordings from single cells. An important feature of this program is the attempt to correlate the antomical and physiological data in a single primate species. This study includes the determination of the organization of the connectional and functional-interrelationships of the brainstem, thalamus and neocortex. First the segregated and overlapping connections between the subdivisions of these levels of the brain will be described and then the functional role of each will be determined. We wish to determine how the inputs and outputs of these structures are related to the integration of sensory information and how they then couple into and influence the oculomotor system. We further wish to identify retinotopically organized subcortical centers which act as links in the sensorimotor and multimodal pathways to the cortex, in addition to determining how these centers and the various cortical areas couple into the oculomotor system. While the results of these studies are expected to identify the organization of multimodal and sensorimotor systems involved, for example, in accomodation, attention and discrimination, we also wish to determine the functional and anatomical organization of the extrageniculate inputs to primary visual cortex in order to further understand the organization of the primary component of the sensory visual system.